O / ostentārĭus
adjective

ostentārĭus

fem. ostentāria · neut. ostentārium
relating to prophetic indications; prophetic
of or relating to prophetic indications, prophetic (post-class.): ostentaria novitas (al. ostentatoria), Mart. Cap. 2, § 151.—
a book of prognostics
Subst.: ostentārĭum, ii, n., a book of prognostics: Tuscum, Macr. S. 3, 7: arborarium, id. ib. 2, 16.